cleaned up BIG time, instruction hierachy, better names, DRYd up a lot

This commit is contained in:
Torsten Ruger 2014-04-23 23:40:35 +03:00
parent c98547137b
commit f97205300f
10 changed files with 516 additions and 499 deletions

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@ -1,4 +1,7 @@
require 'asm/instruction' require 'asm/call_instruction'
require 'asm/stack_instruction'
require 'asm/logic_instruction'
require 'asm/memory_instruction'
require 'asm/nodes' require 'asm/nodes'
require 'stream_reader' require 'stream_reader'
require 'stringio' require 'stringio'
@ -6,118 +9,123 @@ require "asm/string_literal"
module Asm module Asm
class ArmAssembler class ArmAssembler
%w(r0 r1 r2 r3 r4 r5 r6 r7 r8 r9 r10 r11 r12
r13 r14 r15 a1 a2 a3 a4 v1 v2 v3 v4 v5 v6
rfp sl fp ip sp lr pc
).each { |reg|
define_method(reg) {
Asm::Register.new(reg)
}
}
def initialize
@values = []
@position = 0 # marks not set
@labels = []
@string_table = {}
end
attr_reader :values , :position
def instruction(clazz,name, *args)
opcode = name.to_s
arg_nodes = []
args.each { |arg|
if (arg.is_a?(Asm::Register))
arg_nodes << arg
elsif (arg.is_a?(Integer))
arg_nodes << Asm::NumLiteral.new(arg)
elsif (arg.is_a?(String))
arg_nodes << add_string(arg)
elsif (arg.is_a?(Asm::Label))
arg_nodes << arg
else
raise 'Invalid argument `%s\' for instruction' % arg.inspect
end
}
add_value clazz.new(opcode , arg_nodes)
end
def self.define_instruction(inst , clazz )
define_method(inst) do |*args|
instruction clazz , inst.to_sym, *args
end
define_method(inst+'s') do |*args|
instruction clazz , (inst+'s').to_sym, *args
end
%w(al eq ne cs mi hi cc pl ls vc lt le ge gt vs).each do |cond_suffix|
define_method(inst+cond_suffix) do |*args|
instruction clazz , (inst+cond_suffix).to_sym, *args
end
define_method(inst+'s'+cond_suffix) do |*args|
instruction clazz , (inst+'s'+cond_suffix).to_sym, *args
end
end
end
["push", "pop"].each do |inst|
define_instruction(inst , StackInstruction)
end
%w(adc add and bic eor orr rsb rsc sbc sub mov mvn cmn cmp teq tst b bl bx
swi str strb ldr ldrb ).each do |inst|
define_instruction(inst , Instruction)
end
def assemble_to_string
#put the strings at the end of the assembled code.
# adding them will fix their position and make them assemble after
@string_table.values.each do |data|
add_value data
end
io = StringIO.new
assemble(io)
io.string
end
def add_string str
value = @string_table[str]
return value if value
data = Asm::StringLiteral.new(str)
@string_table[str] = data
end
def strings
@string_table.values
end
def add_value(val)
val.at(@position)
length = val.length
@position += length
@values << val
end
def label name
label = Label.new(name , self)
@labels << label
label
end
def label! name
label(name).set!
end
def assemble(io)
@values.each do |obj|
obj.assemble io, self
end
end
InstructionTools::REGISTERS.each do |reg , number|
define_method(reg) { Asm::Register.new(reg , number) }
end end
def initialize
@values = []
@position = 0 # marks not set
@labels = []
@string_table = {}
end
attr_reader :values , :position
def instruction(clazz,name, *args)
opcode = name.to_s
arg_nodes = []
args.each do |arg|
if (arg.is_a?(Asm::Register))
arg_nodes << arg
elsif (arg.is_a?(Integer))
arg_nodes << Asm::NumLiteral.new(arg)
elsif (arg.is_a?(String))
arg_nodes << add_string(arg)
elsif (arg.is_a?(Asm::Label))
arg_nodes << arg
else
raise "Invalid argument #{arg.inspect} for instruction"
end
end
add_value clazz.new(opcode , arg_nodes)
end
def self.define_instruction(inst , clazz )
define_method(inst) do |*args|
instruction clazz , inst , *args
end
define_method(inst.to_s+'s') do |*args|
instruction clazz , inst.to_s+'s' , *args
end
InstructionTools::COND_CODES.keys.each do |cond_suffix|
suffix = cond_suffix.to_s
define_method(inst.to_s + suffix) do |*args|
instruction clazz , inst + suffix , *args
end
define_method(inst.to_s + 's'+ suffix) do |*args|
instruction clazz , inst.to_s + 's' + suffix, *args
end
end
end
[:push, :pop].each do |inst|
define_instruction(inst , StackInstruction)
end
[:adc, :add, :and, :bic, :eor, :orr, :rsb, :rsc, :sbc, :sub].each do |inst|
define_instruction(inst , LogicInstruction)
end
[:mov, :mvn].each do |inst|
define_instruction(inst , MoveInstruction)
end
[:cmn, :cmp, :teq, :tst].each do |inst|
define_instruction(inst , CompareInstruction)
end
[:strb, :str , :ldrb, :ldr].each do |inst|
define_instruction(inst , MemoryInstruction)
end
[:b, :bl , :swi].each do |inst|
define_instruction(inst , CallInstruction)
end
def assemble_to_string
#put the strings at the end of the assembled code.
# adding them will fix their position and make them assemble after
@string_table.values.each do |data|
add_value data
end
io = StringIO.new
assemble(io)
io.string
end
def add_string str
value = @string_table[str]
return value if value
data = Asm::StringLiteral.new(str)
@string_table[str] = data
end
def strings
@string_table.values
end
def add_value(val)
val.at(@position)
length = val.length
@position += length
@values << val
end
def label name
label = Label.new(name , self)
@labels << label
label
end
def label! name
label(name).set!
end
def assemble(io)
@values.each do |obj|
obj.assemble io, self
end
end
end
end end

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@ -0,0 +1,43 @@
module Asm
# ADDRESSING MODE 4 , Calling
class CallInstruction < Instruction
include Asm::InstructionTools
def initialize(opcode , args)
super(opcode,args)
end
def assemble(io, as)
s = @update_status_flag? 1 : 0
case opcode
when :b, :bl
arg = args[0]
if arg.is_a? Label
diff = arg.position - self.position - 8
arg = NumLiteral.new(diff)
end
if (arg.is_a?(Asm::NumLiteral))
jmp_val = arg.value >> 2
packed = [jmp_val].pack('l')
# signed 32-bit, condense to 24-bit
# TODO add check that the value fits into 24 bits
io << packed[0,3]
else
raise "else not coded #{arg.inspect}"
end
io.write_uint8 OPCODES[opcode] | (COND_CODES[@cond] << 4)
when :swi
arg = args[0]
if (arg.is_a?(Asm::NumLiteral))
packed = [arg.value].pack('L')[0,3]
io << packed
io.write_uint8 0b1111 | (COND_CODES[@cond] << 4)
else
raise Asm::AssemblyError.new("invalid operand argument expected literal not #{arg}")
end
end
end
end#class
end

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@ -1,110 +1,47 @@
require "asm/assembly_error" require "asm/assembly_error"
require "asm/instruction_tools" require "asm/instruction_tools"
require "asm/normal_builder"
require "asm/memory_access_builder"
require "asm/label" require "asm/label"
module Asm module Asm
class Instruction class Instruction
include InstructionTools include InstructionTools
COND_POSTFIXES = Regexp.union(%w(eq ne cs cc mi pl vs vc hi ls ge lt gt le al)).source COND_POSTFIXES = Regexp.union( COND_CODES.keys.collect{|k|k.to_s} ).source
def initialize(opcode , args)
opcode = opcode.downcase def initialize(opcode , args)
@cond = 0b1011 opcode = opcode.to_s.downcase
if (opcode =~ /(#{COND_POSTFIXES})$/) @cond = :al
@cond = $1.to_sym if (opcode =~ /(#{COND_POSTFIXES})$/)
opcode = opcode[0..-3] @cond = $1.to_sym
end unless opcode == 'teq' opcode = opcode[0..-3]
if (opcode =~ /s$/) end unless opcode == 'teq'
@s = true if (opcode =~ /s$/)
opcode = opcode[0..-2] @update_status_flag= 1
else opcode = opcode[0..-2]
@s = false else
end @update_status_flag= 0
@opcode = opcode.downcase.to_sym
@args = args
end
attr_reader :opcode, :args , :position
def affect_status
@s
end
def at position
@position = position
end
def length
4
end
def assemble(io, as)
s = @s ? 1 : 0
case opcode
when :adc, :add, :and, :bic, :eor, :orr, :rsb, :rsc, :sbc, :sub
builder = NormalBuilder.new(OPC_DATA_PROCESSING, OPCODES[opcode], s)
builder.cond = COND_CODES[@cond]
builder.rd = reg_ref(args[0])
builder.rn = reg_ref(args[1])
builder.build_operand args[2] , self.position
builder.assemble io, as
when :cmn, :cmp, :teq, :tst
builder = NormalBuilder.new(OPC_DATA_PROCESSING, OPCODES[opcode], 1)
builder.cond = COND_CODES[@cond]
builder.rn = reg_ref(args[0])
builder.rd = 0
builder.build_operand args[1]
builder.assemble io, as
when :mov, :mvn
builder = NormalBuilder.new(OPC_DATA_PROCESSING, OPCODES[opcode], s)
builder.cond = COND_CODES[@cond]
builder.rn = 0
builder.rd = reg_ref(args[0])
builder.build_operand args[1]
builder.assemble io, as
when :strb, :str
builder = MemoryAccessBuilder.new(OPC_MEMORY_ACCESS, (opcode == :strb ? 1 : 0), 0)
builder.cond = COND_CODES[@cond]
builder.rd = reg_ref(args[1])
builder.build_operand args[0]
builder.assemble io, as, self
when :ldrb, :ldr
builder = MemoryAccessBuilder.new(OPC_MEMORY_ACCESS, (opcode == :ldrb ? 1 : 0), 1)
builder.cond = COND_CODES[@cond]
builder.rd = reg_ref(args[0])
builder.build_operand args[1]
builder.assemble io, as, self
when :b, :bl
arg = args[0]
if arg.is_a? Label
diff = arg.position - self.position - 8
arg = NumLiteral.new(diff)
end
if (arg.is_a?(Asm::NumLiteral))
jmp_val = arg.value >> 2
packed = [jmp_val].pack('l')
# signed 32-bit, condense to 24-bit
# TODO add check that the value fits into 24 bits
io << packed[0,3]
else
raise "else not coded #{arg.inspect}"
end
io.write_uint8 OPCODES[opcode] | (COND_CODES[@cond] << 4)
when :swi
arg = args[0]
if (arg.is_a?(Asm::NumLiteral))
packed = [arg.value].pack('L')[0,3]
io << packed
io.write_uint8 0b1111 | (COND_CODES[@cond] << 4)
else
raise Asm::AssemblyError.new("invalid operand argument expected literal not #{arg}")
end
else
raise Asm::AssemblyError.new("unknown instruction #{opcode} #{self}")
end
end end
@opcode = opcode.downcase.to_sym
@args = args
@operand = 0
end end
attr_reader :opcode, :args , :position , :cond , :operand , :update_status_flag
def affect_status
@s
end
def at position
@position = position
end
def length
4
end
def assemble(io, as)
raise "Abstract class, should not be called/instantiated #{self.inspect}"
end
end
end end

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@ -1,81 +1,86 @@
module Asm module Asm
module InstructionTools module InstructionTools
OPCODES = { OPCODES = {
:adc => 0b0101, :add => 0b0100, :adc => 0b0101, :add => 0b0100,
:and => 0b0000, :bic => 0b1110, :and => 0b0000, :bic => 0b1110,
:eor => 0b0001, :orr => 0b1100, :eor => 0b0001, :orr => 0b1100,
:rsb => 0b0011, :rsc => 0b0111, :rsb => 0b0011, :rsc => 0b0111,
:sbc => 0b0110, :sub => 0b0010, :sbc => 0b0110, :sub => 0b0010,
# for these Rn is sbz (should be zero) # for these Rn is sbz (should be zero)
:mov => 0b1101, :mov => 0b1101,
:mvn => 0b1111, :mvn => 0b1111,
# for these Rd is sbz and S=1 # for these Rd is sbz and S=1
:cmn => 0b1011, :cmn => 0b1011,
:cmp => 0b1010, :cmp => 0b1010,
:teq => 0b1001, :teq => 0b1001,
:tst => 0b1000, :tst => 0b1000,
:b => 0b1010, :b => 0b1010,
:bl => 0b1011, :bl => 0b1011,
:bx => 0b00010010 :bx => 0b00010010
} }
COND_CODES = { #return the bit patter that the cpu uses for the current instruction @opcode
:al => 0b1110, :eq => 0b0000, def op_bit_code
:ne => 0b0001, :cs => 0b0010, OPCODES[@opcode] or throw "no code found for #{@opcode.inspect}"
:mi => 0b0100, :hi => 0b1000,
:cc => 0b0011, :pl => 0b0101,
:ls => 0b1001, :vc => 0b0111,
:lt => 0b1011, :le => 0b1101,
:ge => 0b1010, :gt => 0b1100,
:vs => 0b0110
}
OPC_DATA_PROCESSING = 0b00
OPC_MEMORY_ACCESS = 0b01
OPC_STACK = 0b10
def reg_ref(arg)
if (not arg.is_a?(Asm::Register))
raise Asm::AssemblyError.new("argument must be a register not #{arg}")
end
ref =
{'r0' => 0, 'r1' => 1, 'r2' => 2, 'r3' => 3, 'r4' => 4, 'r5' => 5,
'r6' => 6, 'r7' => 7, 'r8' => 8, 'r9' => 9, 'r10' => 10, 'r11' => 11,
'r12' => 12, 'r13' => 13, 'r14' => 14, 'r15' => 15, 'a1' => 0, 'a2' => 1,
'a3' => 2, 'a4' => 3, 'v1' => 4, 'v2' => 5, 'v3' => 6, 'v4' => 7, 'v5' => 8,
'v6' => 9, 'rfp' => 9, 'sl' => 10, 'fp' => 11, 'ip' => 12, 'sp' => 13,
'lr' => 14, 'pc' => 15}[arg.name.downcase]
if (not ref)
raise Asm::AssemblyError.new("unknown register #{arg}")
end
ref
end
end end
def calculate_u8_with_rr(arg) #codition codes can be applied to many instructions and thus save branches
parts = arg.value.to_s(2).rjust(32,'0').scan(/^(0*)(.+?)0*$/).flatten # :al => always , :eq => equal and so on
pre_zeros = parts[0].length # eq mov if equal :moveq r1 r2 (also exists as function) will only execute if the last operation was 0
imm_len = parts[1].length COND_CODES = {
if ((pre_zeros+imm_len) % 2 == 1) :al => 0b1110, :eq => 0b0000,
u8_imm = (parts[1]+'0').to_i(2) :ne => 0b0001, :cs => 0b0010,
imm_len += 1 :mi => 0b0100, :hi => 0b1000,
else :cc => 0b0011, :pl => 0b0101,
u8_imm = parts[1].to_i(2) :ls => 0b1001, :vc => 0b0111,
end :lt => 0b1011, :le => 0b1101,
if (u8_imm.fits_u8?) :ge => 0b1010, :gt => 0b1100,
# can do! :vs => 0b0110
rot_imm = (pre_zeros+imm_len) / 2 }
if (rot_imm > 15) #return the bit pattern for the @cond variable, which signals the conditional code
return nil def cond_bit_code
end COND_CODES[@cond] or throw "no code found for #{@cond}"
return u8_imm | (rot_imm << 8)
else
return nil
end
end end
OPC_DATA_PROCESSING = 0b00
OPC_MEMORY_ACCESS = 0b01
OPC_STACK = 0b10
REGISTERS = { 'r0' => 0, 'r1' => 1, 'r2' => 2, 'r3' => 3, 'r4' => 4, 'r5' => 5,
'r6' => 6, 'r7' => 7, 'r8' => 8, 'r9' => 9, 'r10' => 10, 'r11' => 11,
'r12' => 12, 'r13' => 13, 'r14' => 14, 'r15' => 15, 'a1' => 0, 'a2' => 1,
'a3' => 2, 'a4' => 3, 'v1' => 4, 'v2' => 5, 'v3' => 6, 'v4' => 7, 'v5' => 8,
'v6' => 9, 'rfp' => 9, 'sl' => 10, 'fp' => 11, 'ip' => 12, 'sp' => 13,
'lr' => 14, 'pc' => 15 }
def reg name
raise "no such register #{reg}" unless REGISTERS[name]
Asm::Register.new(name , REGISTERS[name])
end
def calculate_u8_with_rr(arg)
parts = arg.value.to_s(2).rjust(32,'0').scan(/^(0*)(.+?)0*$/).flatten
pre_zeros = parts[0].length
imm_len = parts[1].length
if ((pre_zeros+imm_len) % 2 == 1)
u8_imm = (parts[1]+'0').to_i(2)
imm_len += 1
else
u8_imm = parts[1].to_i(2)
end
if (u8_imm.fits_u8?)
# can do!
rot_imm = (pre_zeros+imm_len) / 2
if (rot_imm > 15)
return nil
end
return u8_imm | (rot_imm << 8)
else
return nil
end
end
end
end end

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@ -0,0 +1,105 @@
module Asm
# ADDRESSING MODE 1
# Logic ,Maths, Move and compare instructions (last three below)
class LogicInstruction < Instruction
include Asm::InstructionTools
def initialize( opcode , args)
super(opcode , args)
@inst_class = OPC_DATA_PROCESSING
@i = 0
@rd = args[0]
end
attr_accessor :inst_class, :i, :rn, :rd
# Build representation for source value
def build
@rn = args[1]
do_build args[2]
end
#(stays in subclases, while build is overriden to provide different arguments)
def do_build(arg)
if arg.is_a?(Asm::StringLiteral)
# do pc relative addressing with the difference to the instuction
# 8 is for the funny pipeline adjustment (ie oc pointing to fetch and not execute)
arg = Asm::NumLiteral.new( arg.position - self.position - 8 )
end
if (arg.is_a?(Asm::NumLiteral))
if (arg.value.fits_u8?)
# no shifting needed
@operand = arg.value
@i = 1
elsif (op_with_rot = calculate_u8_with_rr(arg))
@operand = op_with_rot
@i = 1
else
raise Asm::AssemblyError.new("cannot fit numeric literal argument in operand #{arg}")
end
elsif (arg.is_a?(Asm::Register))
@operand = arg
@i = 0
elsif (arg.is_a?(Asm::Shift))
rm_ref = arg.argument
@i = 0
shift_op = {'lsl' => 0b000, 'lsr' => 0b010, 'asr' => 0b100,
'ror' => 0b110, 'rrx' => 0b110}[arg.type]
if (arg.type == 'ror' and arg.value.nil?)
# ror #0 == rrx
raise Asm::AssemblyError.new('cannot rotate by zero', arg)
end
arg1 = arg.value
if (arg1.is_a?(Asm::NumLiteral))
if (arg1.value >= 32)
raise Asm::AssemblyError.new('cannot shift by more than 31', arg1)
end
shift_imm = arg1.value
elsif (arg1.is_a?(Asm::Register))
shift_op val |= 0x1;
shift_imm = arg1.number << 1
elsif (arg.type == 'rrx')
shift_imm = 0
end
@operand = rm_ref | (shift_op << 4) | (shift_imm << 4+3)
else
raise Asm::AssemblyError.new("invalid operand argument #{arg.inspect}")
end
end
def assemble(io, as)
build
val = operand.is_a?(Register) ? operand.bits : operand
val |= (rd.bits << 12)
val |= (rn.bits << 12+4)
val |= (update_status_flag << 12+4+4)#20
val |= (op_bit_code << 12+4+4 +1)
val |= (i << 12+4+4 +1+4)
val |= (inst_class << 12+4+4 +1+4+1)
val |= (cond_bit_code << 12+4+4 +1+4+1+2)
io.write_uint32 val
end
end
class CompareInstruction < LogicInstruction
def initialize( opcode , args)
super(opcode , args)
@update_status_flag = 1
@rn = args[0]
@rd = reg "r0"
end
def build
do_build args[1]
end
end
class MoveInstruction < LogicInstruction
def initialize( opcode , args)
super(opcode , args)
@rn = reg "r0" # register zero = zero bit pattern
end
def build
do_build args[1]
end
end
end

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@ -1,74 +0,0 @@
require "asm/nodes"
module Asm
# ADDRESSING MODE 2
# Implemented: immediate offset with offset=0
class MemoryAccessBuilder
include Asm::InstructionTools
def initialize(inst_class, byte_access, load_store)
@cond = 0b1110
@inst_class = 0
@i = 0 #I flag (third bit)
@pre_post_index = 0 #P flag
@add_offset = 0 #U flag
@byte_access = 0 #B flag
@w = 0 #W flag
@load_store = 0 #L flag
@rn = 0
@rd = 0
@operand = 0
@inst_class = inst_class
@byte_access = byte_access
@load_store = load_store
end
attr_accessor :cond, :inst_class, :i, :pre_post_index, :add_offset,
:byte_access, :w, :load_store, :rn, :rd, :operand
# Build representation for target address
def build_operand(arg)
#str / ldr are _serious instructions. With BIG possibilities not half are implemented
@i = 0
@pre_post_index = 0
@w = 0
@operand = 0
if (arg.is_a?(Asm::Register))
@rn = reg_ref(arg)
if(arg.offset != 0)
@operand = arg.offset
if (@operand < 0)
@add_offset = 0
#TODO test/check/understand
@operand *= -1
else
@add_offset = 1
end
if (@operand.abs > 4095)
raise Asm::AssemblyError.new("reference offset too large/small (max 4095) #{argr.right}" )
end
end
elsif (arg.is_a?(Asm::Label) or arg.is_a?(Asm::NumLiteral))
@pre_post_index = 1
@rn = 15 # pc
@use_addrtable_reloc = true
@addrtable_reloc_target = arg
else
raise Asm::AssemblyError.new("invalid operand argument #{arg.inspect}")
end
end
def assemble(io, as, inst)
#not sure about these 2 constants. They produce the correct output for str r0 , r1
# but i can't help thinking that that is because they are not used in that instruction and
# so it doesn't matter. Will see
@add_offset = 1
@pre_post_index = 1
val = operand | (rd << 12 ) | (rn << 12 + 4) |
(load_store << 12+4+4) | (w << 12+4+4+1) |
(byte_access << 12+4+4+1+1) | (add_offset << 12+4+4+1+1+1) |
(pre_post_index << 12+4+4+1+1+1+1) | (i << 12+4+4+1+1+1+1+1) |
(inst_class << 12+4+4+1+1+1+1+1+1) | (cond << 12+4+4+1+1+1+1+1+1+2)
io.write_uint32 val
end
end
end

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require "asm/nodes"
module Asm
# ADDRESSING MODE 2
# Implemented: immediate offset with offset=0
class MemoryInstruction < Instruction
include Asm::InstructionTools
def initialize(opcode , args)
super( opcode , args )
@inst_class = OPC_MEMORY_ACCESS
@i = 0 #I flag (third bit)
@pre_post_index = 0 #P flag
@add_offset = 0 #U flag
@byte_access = opcode.to_s[-1] == "b" ? 1 : 0 #B (byte) flag
@w = 0 #W flag
@is_load = opcode.to_s[0] == "l" ? 1 : 0 #L (load) flag
@rn = reg "r0" # register zero = zero bit pattern
@rd = reg "r0" # register zero = zero bit pattern
end
attr_accessor :inst_class, :i, :pre_post_index, :add_offset,
:byte_access, :w, :is_load, :rn, :rd
# Build representation for target address
def build
if( @is_load )
@rd = args[0]
arg = args[1]
else #store
@rd = args[1]
arg = args[0]
end
#str / ldr are _serious instructions. With BIG possibilities not half are implemented
if (arg.is_a?(Asm::Register))
@rn = arg
if(arg.offset != 0)
@operand = arg.offset
if (@operand < 0)
@add_offset = 0
#TODO test/check/understand
@operand *= -1
else
@add_offset = 1
end
if (@operand.abs > 4095)
raise Asm::AssemblyError.new("reference offset too large/small (max 4095) #{argr.right}" )
end
end
elsif (arg.is_a?(Asm::Label) or arg.is_a?(Asm::NumLiteral))
@pre_post_index = 1
@rn = pc
@use_addrtable_reloc = true
@addrtable_reloc_target = arg
else
raise Asm::AssemblyError.new("invalid operand argument #{arg.inspect}")
end
end
def assemble(io, as)
build
#not sure about these 2 constants. They produce the correct output for str r0 , r1
# but i can't help thinking that that is because they are not used in that instruction and
# so it doesn't matter. Will see
@add_offset = 1
@pre_post_index = 1
val = operand
val |= (rd.bits << 12 )
val |= (rn.bits << 12+4) #16
val |= (is_load << 12+4 +4)
val |= (w << 12+4 +4+1)
val |= (byte_access << 12+4 +4+1+1)
val |= (add_offset << 12+4 +4+1+1+1)
val |= (pre_post_index << 12+4 +4+1+1+1+1)#24
val |= (i << 12+4 +4+1+1+1+1 +1)
val |= (inst_class << 12+4 +4+1+1+1+1 +1+1)
val |= (cond_bit_code << 12+4 +4+1+1+1+1 +1+1+2)
io.write_uint32 val
end
end
end

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@ -9,9 +9,10 @@ module Asm
# Arm has addressing modes abound, and so can add to a register before actually using it # Arm has addressing modes abound, and so can add to a register before actually using it
# If can actually shift or indeed shift what it adds, but not implemented # If can actually shift or indeed shift what it adds, but not implemented
class Register class Register
attr_accessor :name , :offset attr_accessor :name , :offset , :bits
def initialize name def initialize name , bits
@name = name @name = name
@bits = bits
@offset = 0 @offset = 0
end end

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@ -1,82 +0,0 @@
module Asm
# ADDRESSING MODE 1
# Complete!
class NormalBuilder
include Asm::InstructionTools
def initialize(inst_class, opcode, s)
@cond = 0b1110
@inst_class = 0
@i = 0
@s = 0
@rn = 0
@rd = 0
@operand = 0
@inst_class = inst_class
@opcode = opcode
@s = s
end
attr_accessor :cond, :inst_class, :i, :opcode, :s,
:rn, :rd, :operand
# Build representation for source value
def build_operand(arg , position = 0)
#position only needed for calculating relative addresses to data objects
#there is a design stink here which makes my head ache. But shanti shanti
if arg.is_a?(Asm::StringLiteral)
# do pc relative addressing with the difference to the instuction
# 8 is for the funny pipeline adjustment (ie oc pointing to fetch and not execute)
arg = Asm::NumLiteral.new( arg.position - position - 8 )
end
if (arg.is_a?(Asm::NumLiteral))
if (arg.value.fits_u8?)
# no shifting needed
@operand = arg.value
@i = 1
elsif (op_with_rot = calculate_u8_with_rr(arg))
@operand = op_with_rot
@i = 1
else
raise Asm::AssemblyError.new("cannot fit numeric literal argument in operand #{arg}")
end
elsif (arg.is_a?(Asm::Register))
@operand = reg_ref(arg)
@i = 0
elsif (arg.is_a?(Asm::Shift))
rm_ref = reg_ref(arg.argument)
@i = 0
shift_op = {'lsl' => 0b000, 'lsr' => 0b010, 'asr' => 0b100,
'ror' => 0b110, 'rrx' => 0b110}[arg.type]
if (arg.type == 'ror' and arg.value.nil?)
# ror #0 == rrx
raise Asm::AssemblyError.new('cannot rotate by zero', arg)
end
arg1 = arg.value
if (arg1.is_a?(Asm::NumLiteral))
if (arg1.value >= 32)
raise Asm::AssemblyError.new('cannot shift by more than 31', arg1)
end
shift_imm = arg1.value
elsif (arg1.is_a?(Asm::Register))
shift_op |= 0x1;
shift_imm = reg_ref(arg1) << 1
elsif (arg.type == 'rrx')
shift_imm = 0
end
@operand = rm_ref | (shift_op << 4) | (shift_imm << 4+3)
else
raise Asm::AssemblyError.new("invalid operand argument #{arg.inspect}")
end
end
def assemble(io, as)
val = operand | (rd << 12) | (rn << 12+4) |
(s << 12+4+4) | (opcode << 12+4+4+1) |
(i << 12+4+4+1+4) | (inst_class << 12+4+4+1+4+1) |
(cond << 12+4+4+1+4+1+2)
io.write_uint32 val
end
end
end

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@ -1,65 +1,59 @@
require "asm/instruction" require "asm/instruction"
module Asm module Asm
# ADDRESSING MODE 4 # ADDRESSING MODE 4
class StackInstruction < Instruction class StackInstruction < Instruction
include Asm::InstructionTools include Asm::InstructionTools
def initialize(opcode , args) def initialize(opcode , args)
super(opcode,args) super(opcode,args)
@operand = 0 @inst_class = Asm::Instruction::OPC_STACK
@cond = 0b1110 @update_status_flag= 0
@inst_class = Asm::Instruction::OPC_STACK @rn = reg "r0" # register zero = zero bit pattern
@s = 0 # downward growing, decrement before memory access
@rn = 0 # official ARM style stack as used by gas
# downward growing, decrement before memory access @write_base = 1
# official ARM style stack as used by gas if (opcode == :push)
@write_base = 1 @pre_post_index = 1
if (opcode == :push) @up_down = 0
@pre_post_index = 1 @is_pop = 0
@up_down = 0 else #pop
@store_load = 0 @pre_post_index = 0
else #pop @up_down = 1
@pre_post_index = 0 @is_pop = 1
@up_down = 1
@store_load = 1
end
end end
attr_accessor :cond, :inst_class, :pre_post_index, :up_down,
:s, :write_base, :store_load, :rn, :operand
def assemble(io, as)
cond = @cond.is_a?(Symbol) ? COND_CODES[@cond] : @cond
rn = 13 # sp
build_operand args
#assemble of old
val = @operand
val |= (rn << 16)
val |= (store_load << 16+4) #20
val |= (write_base << 16+4+ 1)
val |= (s << 16+4+ 1+1)
val |= (up_down << 16+4+ 1+1+1)
val |= (pre_post_index << 16+4+ 1+1+1+1)#24
val |= (inst_class << 16+4+ 1+1+1+1 +2)
val |= (cond << 16+4+ 1+1+1+1 +2+2)
puts "#{self.inspect}"
io.write_uint32 val
end
private
# Build representation for source value
def build_operand(arg)
if (arg.is_a?(Array))
@operand = 0
arg.each do |reg |
reg = reg_ref(reg)
@operand |= (1 << reg)
end
else
raise Asm::AssemblyError.new("invalid operand argument #{arg.inspect}")
end
end
end end
attr_accessor :cond, :inst_class, :pre_post_index, :up_down,
:update_status_flag, :write_base, :is_pop, :rn, :operand
def assemble(io, as)
build
cond = @cond.is_a?(Symbol) ? COND_CODES[@cond] : @cond
rn = reg "sp" # sp register
#assemble of old
val = operand
val |= (rn.bits << 16)
val |= (is_pop << 16+4) #20
val |= (write_base << 16+4+ 1)
val |= (update_status_flag << 16+4+ 1+1)
val |= (up_down << 16+4+ 1+1+1)
val |= (pre_post_index << 16+4+ 1+1+1+1)#24
val |= (inst_class << 16+4+ 1+1+1+1 +2)
val |= (cond << 16+4+ 1+1+1+1 +2+2)
io.write_uint32 val
end
private
# Build representation for source value
def build
if (args.is_a?(Array))
@operand = 0
args.each do |reg |
@operand |= (1 << reg.bits)
end
else
raise Asm::AssemblyError.new("invalid operand argument #{args.inspect}")
end
end
end
end end